Type 2 diabetes mellitus (T2DM) in middle-aged individuals has been consistently associated with deficits in recent memory, attention, executive function, and cognitive efficiency. Insulin resistance (IR) is a progressive pre-diabetic condition. We have strong preliminary evidence that similar cognitive problems are also present among obese adolescents with IR relative to matched non-insulin resistant groups. The purpose of the proposed study is to rigorously establish the nature of the cognitive impairments present among obese adolescents with IR and by means of a systematic and standardized neuropsychological and MRI-approach to further characterize the brain substrates for those abnormalities. In addition, we propose to ascertain whether, relative to matched lean adolescents, obese adolescents without insulin resistance have detectable cognitive impairments. Obesity and IR are associated with inflammation. Thus, we will also assess whether inflammation mediates some of the associations between IR (and/or obesity) and brain dysfunction in adolescence. We seek funds to mitigate the effects of Hurricane Sandy and facilitate the successful completion of the Specific Aims of our proposal, which are: Specific Aim I: To determine whether obese adolescents with insulin resistance have lower performance on memory and other cognitive domains relative to matched obese non-insulin resistant and lean adolescents. Specific Aim II: To determine whether obese adolescents with insulin resistance have MRI-based hippocampal volume reductions, gray matter reductions, and white matter abnormalities. Specific Aim III: To determine whether among obese adolescents markers of inflammation mediate the hypothesized links between insulin resistance and reductions in cognitive performance, hippocampal volume reductions, reductions in gray matter, and reductions in white matter integrity. Funds will be used for: - Salary of personnel for time spent either in lockout, damage assessment, re-establishing the laboratory, running additional subjects to complete the aims - Supplies costs that are needed to complete the aims; - Extra assays on stored samples needed to complete the aims We estimate that we will need 6 months to make up for the time lost due to Sandy.